Container unloading

ABSTRACT

An apparatus for unloading the contents of containers, particularly but not exclusively baggage or cargo containers used in aircraft. The apparatus comprises a decanter apparatus for tilting each container toward an open side thereof at a discharge station and a fence arranged to hold back the contents of at least one region of said container until the contents of at least one other region have been discharged as a result of the tilting, the fence being arranged for relative vertical movement with respect to said open side to permit controlled discharge of the regions of said container in a predetermined order. The loaded containers are placed in turn on the decanter apparatus in the upright position and then tilted towards an open side of the container, the fence being arranged initially to close the open side except for the upper part thereof, and the fence is then moved with respect to the container side thus permitting progressive discharge of the container. Means are provided which are actuated by discharged articles to control the speed of the conveyor and so regulate the rate at which articles leave the conveyor and means may also be provided which control the relative movement of the fence with respect to the container side in synchronism with the speed of the conveyor.

United States Patent 1 91 Rooke et al.

[451 Feb. 20, 1973 [54] CONTAINER UNLOADING [75} Inventors: SydneyWilliam Rooke, Ronald Frances Coston, both of Erith, Kent, England n[73] Assignee: Sonex Ltd., Kent, England 221 Filed: Nov. 17,1971 21Appl.No.: 199,568

Related U.S. Application Data -[63] Continuation-impart of Ser. No.11,956, Feb. 17,

1970, Pat. No. 3,651,967.

[52] U.S. Cl. ..2l4/307, 198/37, 214/52 R, 214/314 [51] Int. Cl. ..B65b21/02 [58] Field of Search ..2l4/8.5 A, 16.4 R, 306, 307, 214/314, 52 R;221/91; 198/37 Primary Examiner-Robert G. Sheridan AssistantExaminer-Lawrence J. Oresky Attorney-Elliot l. Pollock et al.

[57] ABSTRACT An apparatus for unloading the contents of containers,particularly but not exclusively baggage or cargo containers used inaircraft. The apparatus comprises a decanter apparatus for tilting eachcontainer toward an open side thereof at a discharge station and a fencearranged to hold back the contents of at least one region of saidcontainer until the contents of at least one other region have beendischarged as a result of the tilting, the fence being arranged forrelative vertical movement with respect to said open side to permitcontrolled discharge of the regions of said container in a predeterminedorder. The loaded containers are placed in turn on the decanterapparatus in the upright position and then tilted towards an open sideof the container, the fence being arranged initially to close the openside except for the upper part thereof, and the fence is then moved withrespect to the container side thus permitting progressive discharge ofthe container. Means are provided which are actuated by dischargedarticles to control the speed of the con veyor and so regulate the rateat which articles leave the conveyor and means may also be providedwhich control the relative movement of the fence with respect to thecontainer side in synchronism with the speed of the conveyor.

11 Claims, 15 Drawing Figures PATENTED FEBZU 1975 SHEET 0 3 OF PATENTEI]FEB 2 01973 SHEET E L OF 11 PATENTED $717, 2 70 SEEN C5 HF 11 PATENTEDFEB20|973 SHEET GSUF 11 PATENTED FEBZO I973 IUUF 11 SHEET PATENTEDFEBZOIB'IS PATENTEDFEBZOW $717,270

SHEET 11C? 11 FIG. l5.

CONTAINER UNLOADING RELATED application.

sively baggage or cargo containers used in aircraft in .0

which difficulty has been experienced due to the sudden delivery of thecontents of a container, this invention being concerned with controllingthe speed of discharge to prevent this occurrence and improve delivery.

According to our co-pending invention, Ser. No. 11956 filed Feb. 19,1970, now US. Pat. No. 3,651,967 there is provided an apparatus forunloading the contents of containers, comprising a decanter apparatusfor tilting each container towards an open side thereof at a dischargestation and a fence arranged to hold back the contents of at least oneregion of said container until the contents of at least one other regionhave been discharged as a result of the tilting, the fence beingarranged for relative movement with respect to said open side to permitdischarge of the regions of said container in a predetermined order.Advantageously, in that invention a conveyor onto which the saidcontents are thus discharged is arranged to be lowered in conjunctionwith the said fence and with a chute projecting from and aligned withthe upper edge of the fence.

This invention is concerned with the apparatus of our earlierapplication No. 11956, now US. Pat. No. 3,651,976 and relates to afurther development of the apparatus in which means are provided bywhich the speed of the discharge conveyor is regulated to control therate of flow of the articles. These speed regulating means may also beusedito vary the rate at which the relative movement of the fence withrespect to the container side is effected.

ln a first embodiment of the invention, the containers are placed inturn on the decanter apparatus in the upright position and then tiltedtowards an open side of the container against a fence which is arrangedinitially to close the open side except for the upper part thereof, andis then poved downwardly towards the container base thus permittingprogressive discharge of the container, the contents being delivered toa chute attached to the fence and which directs the container contentsto suitable delivery means. The empty container is then returned to theupright condition and discharged from the decanter.

In a second embodiment of the invention, the fence and chute form a partof the decanter apparatus and are tilted into the discharge attitudewith the contalner, which is then moved upwards past the fence, by whichmovement discharge of the container contents is controlled. The emptycontainer is then lowered and returned to the upright position forsubsequent discharge from the decanter.

In a third embodiment of the invention, the fence forms a part of thedecanter and is swung, with the container, into the tilted position andinto alignment with the chute, the container then being elevated in thetilted position as in the previous embodiment. Means may also beprovided which as well as tilting the container towards the open side,are arranged to tilt the container towards one end; this permitsunloading successive regions of the container under greater controlparticularly where the container is divided into a number of regions bycolumns or by partitions which do not have smooth surfaces.

The containers may be divided horizontally into two or morecompartments, and they may be further divided by a vertical partitioninto two sets of compartments or parts back to back, them similarprovision may be made for the tilting of each container first towardsone open side and then towards the other open side, such provisionincluding in each case a fence operating in the manner set forth above.

In an alternative arrangement the fence may be arranged to move bodilywith respect to the container from below upwards.

The speed of the discharge conveyor is controllable for example, bymeans of a light ray which is interrupted by articles travelling fromthe chute to the delivery point in order to establish a maximum rate offlow which may be for example 30 articles per minute.

The speed of the empty conveyor is initially near its maximum, and whenthe light beam is interrupted by the first article, such as a mail bag atime delay is activated and the conveyor is slowed until both the lightbeam is freed and the time delay has expired at which time the conveyorwill accelerate to its full speed. Thus unless both the beam is made andthe time delay has expired, the conveyor will run at its slower speed,so slowing down the rate at which articles are taken from the decanterand fed to the delivery point. Typically the time delay is l or 2seconds. The light beam is located across the conveyor at theappropriate height to be interrupted by the articles which may be mailbags, and spaced approximately the length of one article from the outputend of the conveyor.

In a further embodiment of the invention, the movement of the fence withrespect to the side of the container is either stopped completely ordecelerated when the light beam is interrupted. As soon as the lightbeam is re-made and the time delay has expired the movement of the fenceis re-started or accelerated to its desired speed to effect thecontrolled unloading of the container.

It is particularly advantageous if the upper edge of the fence is higherat one end than the other, thus giving greater graduation of theunloading process, the edge of the fence being either continuouslystraight or curved, or being formed as a series of steps to achieve thesame purpose.

In a modified embodiment of the invention, the fence may consist of anundriven conveyor belt, supported on rollers carried in sliding guidesand one flight of which has a surface area equal to that of the side ofthe container and which thus in one position covers the while containerside. In operation, the two rollers are moved bodily together across thecontainer side, progressively uncovering this part of the container,until the belt has been fully moved to one side exposing the wholecontainer side and permitting it to be completely emptied. Such anarrangement eliminates any possibility of wear or damage to articles inthe container caused by drag or friction due to contact with the fence.

The invention permits of expeditious discharge of, say, passengersluggage from such containers by simple means and of the forwarding ofsuch luggage to a distributing, sorting or collection point or pointswith a minimum of difficulty.

Embodiments of the invention will now be more fully described by way ofexample and with reference to the accompanying drawings, in which;

FIGS. 1 and 2 are a plan and side elevation respectively of one form ofcontainer unloading apparatus.

FIGs. 3, 4 and 5 are end elevations of the apparatus shown in FIGS. 1and 2 in successive stages of unloadmg,

FIGS. 6 and to are views similar to those of FIGS. 1 to S ofa secondembodiment of the invention.

FIGS. 11 to 13 are end elevations similar to those of FIGS. 3 to 5 of athird embodiment of the invention, and

FIG. 14 is a side elevation of the apparatus shown in FIGS. 11 to 13,and

FIG. 15 is a side elevation of an alternative discharge arrangement.

In the following description, it will be assumed in each instance thatthe container is sub-divided horizontally by two shelves into threecompartments. It will be apparent that further sub-division orcombinations thereof are possible within the scope of the invention.

Referring firstly to FIGS. 1 to 5, the loaded containers C are fed, fromfor example an aircraft, to a conveyor I and delivered in turn to adecanter apparatus. In this embodiment the conveyor comprises a poweredindexing chain conveyor with drive dogs 2, the containers beingsupported on wheeled trolleys 3, the drive dogs 2 being spring loaded toallow each container and its trolley 3 to be pushed into position in thedecanter apparatus 4.

The decanter comprises an outwardly tiltable cradle base 5 carried onrockable arms 6, the tilting of the eradle about the bearings 7 being bymeans of hydraulic or pneumatic jacks 8, each trolley 3 being located onthe cradle 5 by wheel support pads held in the feed position by fixedblocks or other suitable means such as clamps.

When the container is in position on the cradle 5, it adjoins a fence 9which initially closes the lower part of the open side of the containeruntil the container and fence have been raised from the upright positionshown in FIG. 3 into the tilted position in which the container is to beemptied.

The fence 9 is lowered with respect to the adjacent open side of thecontainer by means of hydraylic or pneumatic jacks 10 which thus permitsprogressive discharge of successive regions of the container as thefence 9 descends.

FIG. 3 shows a container in position on the decanter cradle 5, beforethe decanter has been tilted, and with the fence 9 therefore in itsrelatively uppermost position. Adjoining the upper edge of the fence 9is a chute 13 which delivers articles released by the fence 9 to adischarge conveyor 14, the tail end of which is supported in slides 15provided on the fence 9 and which is driven at its head end by a motor16.

The chute 13 may be constructed entirely of fixed panels. Alternativelythe floor of the chute may include a form of conveyor for example adriven belt or band, or a series of parallel rollers which may be drivenor idle. This arrangement will reduce or even eliminate friction betweenthe chute and articles leaving the fence on their way to the dischargeand distribution points.

The discharge conveyor 14 supplies two delivery conveyors l7 separatedby a double plough or watershed 18 which separates the containercontents into two streams.

As shown in FIG. 4, the container on its trolley 3 has been lifted andtilted with its open side towards the chute 13 and against the fence 9,while the fence has been aligned with the upper shelf of the container,so that the contents, for example passenger baggage, of the uppercompartment have slide down the chute 13 on to the re atively widedischarge conveyor 14 and have been fed to the conveyors 17 for eventualsorting or recovery by the owners. In this connection, the provision ofthe watershed l8 permits the use of two relatively narrow conveyors,which facilitates changes of direction if desired. It will be evident,however, that the conveyor 14 may be the final discharge, and equallythe chute 13 can be arranged to feed articles to a conveyor which runsparallel to the conveyor chain 1 or to feed any other convenientdistribution system such as a variable slope carousel.

As shown particularly in FIGS. 1 and 4 photo-electric means 143 and 144are disposed on opposite sides of the conveyor 14 and a beam of light145 extends across the conveyor 14 between these photo-electric means143 and 144 at a selected height above the moving surface of conveyor14. The beam 145 is arranged at a suitable height to be interrupted bythe article of least height handled by the apparatus and is spaced fromthe downstream axis 146 by a distance A corresponding to the length ofthe article. While the conveyor 14 is empty it runs at its maximum speeddriven by motor 16 of FIG. 3 and as soon as an article-leaving the chutel3 breaks the light beam 145, a time delay (not shown) is activated andthe conveyor 14 is slowed until both the light beam 145 is freed and thetime delay has expired at which time the conveyor 14 will accelerate toits full speed. Thus unless both the beam 145 is made and the time delayhas expired, the conveyor 14 will run at its slower speed, so slowingdown the rate at which articles are taken from the decanter and fed tothe delivery point. Typically the time delay is l or 2 seconds.

In FIG. 5, the fence 9 is in its lowest position and the bottomcompartment is thus emptied. By providing the sliding guides 15 for theconveyor 14 on the fence 9, the conveyor 14 is maintained in alignmentwith the chute 13, no matter at what height the fence 9 is positioned,so ensuring positive transfer of the container contents from thecontainer to the conveyor 14.

Operation of the hydraulic or pneumatic jacks 10 can be controlled asthey effect the relative movement of the fence 9 with respect to theside of the container together with or independently of the changes inspeed of the conveyor 14. Thus interruption of the light beam 145 caneither completely stop the fence 9 in its relative movement, or thespeed of the relative movement can be varied, that is declelerated whenthe light beam 145 is interrupted. As soon as the light beam 145 isreestablished and the time delay has expired, the relative movement offence 9 with respect to the side of the container is resumed oraccelerated as the loading proceeds.

When the container has been emptied, either totally or to a desireddegree, it is returned to the position shown in FIG. 3 and the trolley 3is engaged by the chain drive dogs 2 and driven out of the decanter, thenext container and trolley being simultaneously placed on the cradle 5.For controlling the entry and removal of the containers, the trolleys 3are guided between rol- I lers 19 supported in rails 20.

In the embodiment shown in FIGS. 6 to 10, the container is arranged tobe raised with respect to the fence and chute, the fence and chuteforming a part of the cradle on which the container is supported duringemptying.

FIG. 6 particularly shows how the edge of the chute 33 may be inclinedto provide additional control of the unloading. The incline may be astraight line as shown. Alternatively it may be curved to a greater orless degree, and in a further modification it may be formed in a seriesof steps, any of these variations enabling greater control over the rateat which articles are discharged from the containers.

As shown in FIGS. 6 and 7, the container is propelled into and out ofthe decanter apparatus on powered rollers 22 contained in the entry andexit section of the conveyor 21 and also in the center portion 23 whichforms part of the decanter apparatus. Once located on the center portion23 of the conveyor 21 the full container is supported in a cradle 24mounted between inclined parallel rails 25. The portion 23 of theconveyor includes a supporting back plate 26 and this back plate,together with the center portion 23 and the cradle 24 are arranged sothat they can be tilted about pivots 27 until the back plate 26 is inalignment with the rails 25, this tilting being achieved by means ofhydraulic or pneumatic jacks 28. The back plate 26 carries pads whichclose gaps in the inclined rails 25, and these rails form guide tracksfor the container during the emptying operation.

The back plate 26 supports a fence 29 which is aligned with the adjacentopen side of the container in the cradle 24, and a chute 33 is alsoattached thereto, the fence having its upper edge arranged at a shallowangle to the horizontal to give gradual discharge to the containercompartment.

When the parts 23 and 24 with the loaded container have been swung tobring the back plate 26 and the inclined rails into alignment, thecradle 24 is supported on rollers 30 which are guided by the rails 25,and the cradle, with the tilted container, are lifted up the inclinedrails 25 by means of winches 31 driven by a motor 32, the cradle beingconnected thereto by cables 35.

Thus the tilted fence 29 and chute 33 remain stationary while thecontainer and cradle 24 slide upwardly past the tilted fence todischarge the container contents on to the chute 33 and thence to aconveyor 34. When the container is empty, it is lowered, on the cradle,until it rests on the center portion 23 of the conveyor, which is the,together with the fence 26 and the chute 33, returned to the uprightposition shown in FIG. 8, from which the empty container is discharged 6and a full one loaded into the decanter, these movements beingcontrolled by limit switches 36.

5 frame which includes the inclined rails 25. Once the loaded containeror the center portion 23 is aligned with the cradle 24 and fence 29 andtilted by means of the jack 28 about the pivots 27, the cradle 24together with its back plate 26 and the fence 29 are brought into theposition in which unloading can commence. The container on its cradle 24is lifted up the inclined rails 25 by the motor driven winches 31 andthe cables 35 while the fence 29 remains stationary and in alignmentwith the fixed chute 33.

The center portion 23 of the conveyor 1 in this embodiment is alsopivotable at one end, transversely with respect to the center line ofthe conveyor and, as shown in FIG. 14, by means of a jack 37 and alinkage 38, a container can be lifted at one end while it is being movedup the rails 25, which provides more efficient control of the emptyingof each part of the container. A spring-loaded back stop 39 is alsoprovided in this embodiment to limit the amount of longitudinal tilting,and to prevent the container from slipping off the cradle 24.

The various embodiments described above, have referred to the emptyingof a container through one open side. However, as already stated, asecond decanter may be provided for emptying the opposite side of acontainer, where the container has a central vertical dividing wall inaddition to or instead of horizontal shelves.

The conveyors 14 or 34 can lead to any suitable discharge or display anddistribution device, such as a variable slope carousel or a suitablycontrolled sorting arrangement.

Instead of the conveyors 17 or 34, the conveyor 14, as shown in FIG. 5can be arranged to feed an intermediate conveyor 141 which delivers itsload to a takeaway conveyor 142 which in this example is a tilted bandarranged at right angles to the intermediate conveyor and inclined, forexample at 40 thereto. In such an example, the conveyors 14 and 141 maybe up to eight feet wide and may have independent or common two-speeddrives, while the take-away conveyor 142 may be four feet wide. Theconveyor 14] can be operated either as a continuous feeder for theconveyor 142, or it can be operated either as an accumulator or storebelt, or in such a way that it evens out the supply of articles to theconveyor 142.

The unloading sequence has typically five stages:

a. the decanter tilts the container with or against the fence.

b. the container contents are discharged under control of the fence.

0. a dwell period allows all the contents to reach the first of thedischarge conveyors.

d. the container is returned to the upright position on its conveyor.

e. the container is pushed out of the decanter and a fresh one is fed into the cradle.

In following these steps, the system operates as the following sequenceshows.

Once the container has reached its initial tilted position, theconveyors 14, 17, 34, 141 and 142 start to run at their predeterminedspeeds. Following this a timer allows the conveyors to run until anarticle has travelled from the container to the take-away conveyor, thisbeing at a speed which ensures correct article supply to the finalconveyor. The conveyors can then be run at a slower speed for theremainder of the unloading cycles. In a particular example, threecontainer shelves feet in width can feed their contents to feet ofconveyor running at 120 feet/minute. This means that for examplearticles can be fed to the conveyor 142 at 320 feetlminute, and thetakeaway conveyor will handle its load at 480 feetminute. in such anexample baggage can be delivered to the conveyor 142, in a period of 24seconds, with an indexed separation between the containers of 8 seconds.

The containers may have slidable panels for closing their otherwise openside or sides, the panels on each side being arranged to move verticallyand/or horizontally, each side thus preferably having two such panels.

By programming the indexing control for both the vertically andhorizontally sliding panels, and starting for example at the upperleft-hand corner of a container side, each container can be unloadedpart-bypart, and in any chosen sequence, in co-ordination with therelative movement between the tilted container and the adjacentfence.

If the direction of sliding of either or both panels is reversible, thenthe number of possible unloading sequences is further increased. Thus,if both are reversible, unloading can commence at any of the fourcorners of the container side. By opening and closing in a chosen order,a practically unlimited number of unloading sequences is available. Theparticular sequence can be so programmed that each succeeding containercan be unloaded in a different sequence.

Loading sequences can be coded for each container at the departurepoint, once for example the relevant container and flight information isavailable, and the in formation can be transmitted by computer link tothe or each arrival point on the route, and the computer system willprogramme the correct identification and unloading sequence of thecontainers on arrival. By suitably coding containers, and even itemswithin them, the contents may be correctly unloaded and fed even toparticular reclamation points or stores, all this being determinedbefore the articles concerned have even left their departure point.Changes due to traffic delay or route alterations can easily be resolvedby the computer without serious effect on the optimum unloadingoperation.

In a modified form of this control of container unloading, each slidingpanel is sub-divided into sections each of which can be operatedindependently.

Thus each sliding panel can be divided horizontally or vertically into anumber of individually operable panels, which as in the previous examplemay be operated in one direction or may be reversible.

All the panels and their sections can be operated by a single drivemeans working through suitable means, such as clutches, each clutchbeing engaged only when and for the length of time necessary. Theclutches can be energized either individually or in groups of two ormore, and obviously all the clutches could be operated simultaneously.

The panels may be vertically and/or horizontally slidable, and thisarrangement also makes a large number of unloading sequences possible.There is no need for all the panels or the section to be of equal size,and any combination of panel size is practical. Operation of the panelsand their sub sections is controllable by suitable means such as thepreviously described computer system, or by punched tape or cards. Theabove handling system permits discrete handling of articles, such aspassengers baggage in small quantities for effective traffic control.The passenger may hold a baggage check with container number andsubdivision on it, this information being fed to the computer at thedeparture airport by the checking staff. The computer in turn willproduce a claim check for retention by the passage until his arrival.

The above described invention is especially suitable for use in thehandling of luggage for aircraft which, particularly in the case of verylarge, high capacity aircraft, have passengers luggage, or commercialfreight, loaded into containers and stowed in the hold of the aircraft,the containers being mechanically handled and for example color coded tofacilitate accurate discharge since speed and efficiency of unloading isof extreme importance in turning round the aircraft, and clearing theincoming passengers and their luggage through the airport with theminimum delay.

We claim:

1. Apparatus for unloading the contents of containers, said apparatuscomprising a decanter apparatus provided with means for tilting eachcontainer about a horizontal axis towards one side thereof at adischarge station and a fence arranged to hold back the contents of atleast one region of said container until the contents of at least oneother region of said container have been discharged as a result of saidtilting about said axis, each loaded container being supported in thedecanter during said tilting towards said side, said fence beingprovided with controllable means operative to effect relative movementof said fence with respect to said side of said container to provideprogressive discharge of the contents of each said region of saidcontainer in a predetermined sequence, a discharge chute attached tosaid fence and a discharge conveyor, the input end of which is incommunication with said chute, means being associated with saiddischarge conveyor to vary the speed of said conveyor betweenpredetermined limits and in response to the presence or absence of thecontents of said container on said discharge conveyor, said means forvarying the speed of said conveyor being adapted to accelerate saidconveyor in the absence of said contents and to decelerate said conveyorin the presence of said contents discharged from said container.

2. Apparatus as claimed in claim 1 wherein said discharge conveyor iscarried in an adjustable mounting provided on said chute and arranged tomaintain, said input end of said discharge conveyor in continuouscommunication with said chute throughout the movement of said fence withrespect to said open side of said container.

3. Apparatus as claimed in claim 1 wherein said decanter apparatusincludes a conveyor means which delivers and discharges said containersto and from said decanter apparatus respectively, a part of saidconveyor being arranged to be tilted with said container.

4. Apparatus as claimed in claim 1 wherein the means which vary thespeed of said discharge conveyor comprise photo-electric means whichgenerate a beam of light extending transversely across said dischargeconveyor at a predetermined height above the load conveying surfacethereof and at a predetermined distance from the discharge end of saiddischarge conveyor, said height and said distance being determined independence on the dimensions of the contents of the container.

5. Apparatus as claimed in claim 1 wherein the controllable meansoperative to effect said relative movement of said fence with respect tosaid side of said container is controlled in synchronism with the meansassociated with said discharge conveyor to vary the speed of saiddischarge conveyor, said controllable means being operative to vary therate of said relative movement of said fence in dependence on thepresence or absence of said container contents of said dischargeconveyor between a predetermined maximum and a station condition.

6. Apparatus as claimed in claim 2 wherein the discharge conveyorreceives the contents from each said region of said container from saidchute and delivers said articles to a delivery conveyor arranged atright angles to said intermediate conveyor, each of said conveyors beingprovided with controllable driving means, said delivery conveyor beingtransversely inclined at least at the point where it is fed by thepreceding conveyor.

7. Apparatus as claimed in claim 2 wherein the discharge conveyorreceives the contents from each said region of said container from saidchute and delivers said articles to an intermediate conveyor, saidintermediate conveyor being arranged to deliver said articles to adelivery conveyor arranged at right angles to said intermediateconveyor, each of said conveyors being provided with controllabledriving means, said delivery conveyor being transversely inclined atleast at the point where it is fed by the preceding conveyor.

8. Apparatus as claimed in claim 1 wherein said decanter apparatus isprovided with tilting means operable to tilt a container in saidapparatus about a second horizontal axis which is perpendicular to theaxis about which said container is tilted towards one side thereof.

9. Apparatus as claimed in claim 1 wherein the edge of the fence isinclined such that one end thereof against the container side is lowerthan the other end.

10. Apparatus as claimed in claim 9 wherein the edge of said fence is aseries of steps.

11. Apparatus as claimed in claim 2 wherein said discharge conveyorconveys its contents to a pair of conveyors the combined width of whichis equal to the width of the discharge conveyor, said pair of conveyorsbeing separated by a double plough or water shed.

@33 UNITED STATES PA'IENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,717,270 D t d February 20, 1973 Inventor) SYDNEY WILLIAM ROOKE andRONALD FRANCES COSTON It is certified that error appears in theaboveidentified patent and that said Letters Patent are hereby correctedas shown below:

The name of the assignee shown on the Patent as "Sonex Ltd., Kent,England" should be "Sovex Ltd. Kent, England" Signed and sealed this17th day of September 1974.

(SEAL) Attest:

MCCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner ofPatents

1. Apparatus for unloading the contents of containers, said apparatuscomprising a decanter apparatus provided with means for tilting eachcontainer about a horizontal axis towards one side thereof at adischarge station and a fence arranged to hold back the contents of atleast one region of said container until the contents of at least oneother region of said container have been discharged as a result of saidtilting about said axis, each loaded container being supported in thedecanter during said tilting towards said side, said fence beingprovided with controllable means operative to effect relative movementof said fence with respect to said side of said container to provideprogressive discharge of the contents of each said region of saidcontainer in a predetermined sequence, a discharge chute attached tosaid fence and a discharge conveyor, the input end of which is incommunication with said chute, means being associated with saiddischarge conveyor to vary the speed of said conveyor betweenpredetermined limits and in response to the presence or absence of thecontents of said container on said discharge conveyor, said means forvarying the speed of said conveyor being adapted to accelerate saidconveyor in the absence of said contents and to decelerate said conveyorin the presence of said contents discharged from said container. 1.Apparatus for unloading the contents of containers, said apparatuscomprising a decanter apparatus provided with means for tilting eachcontainer about a horizontal axis towards one side thereof at adischarge station and a fence arranged to hold back the contents of atleast one region of said container until the contents of at least oneother region of said container have been discharged as a result of saidtilting about said axis, each loaded container being supported in thedecanter during said tilting towards said side, said fence beingprovided with controllable means operative to effect relative movementof said fence with respect to said side of said container to provideprogressive discharge of the contents of each said region of saidcontainer in a predetermined sequence, a discharge chute attached tosaid fence and a discharge conveyor, the input end of which is incommunication with said chute, means being associated with saiddischarge conveyor to vary the speed of said conveyor betweenpredetermined limits and in response to the presence or absence of thecontents of said container on said discharge conveyor, said means forvarying the speed of said conveyor being adapted to accelerate saidconveyor in the absence of said contents and to decelerate said conveyorin the presence of said contents discharged from said container. 2.Apparatus as claimed in claim 1 wherein said discharge conveyor iscarried in an adjustable mounting provided on said chute and arranged tomaintain, said input end of said discharge conveyor in continuouscommunication with said chute throughout the movement of said fence withrespect to said Open side of said container.
 3. Apparatus as claimed inclaim 1 wherein said decanter apparatus includes a conveyor means whichdelivers and discharges said containers to and from said decanterapparatus respectively, a part of said conveyor being arranged to betilted with said container.
 4. Apparatus as claimed in claim 1 whereinthe means which vary the speed of said discharge conveyor comprisephoto-electric means which generate a beam of light extendingtransversely across said discharge conveyor at a predetermined heightabove the load conveying surface thereof and at a predetermined distancefrom the discharge end of said discharge conveyor, said height and saiddistance being determined in dependence on the dimensions of thecontents of the container.
 5. Apparatus as claimed in claim 1 whereinthe controllable means operative to effect said relative movement ofsaid fence with respect to said side of said container is controlled insynchronism with the means associated with said discharge conveyor tovary the speed of said discharge conveyor, said controllable means beingoperative to vary the rate of said relative movement of said fence independence on the presence or absence of said container contents of saiddischarge conveyor between a predetermined maximum and a stationcondition.
 6. Apparatus as claimed in claim 2 wherein the dischargeconveyor receives the contents from each said region of said containerfrom said chute and delivers said articles to a delivery conveyorarranged at right angles to said intermediate conveyor, each of saidconveyors being provided with controllable driving means, said deliveryconveyor being transversely inclined at least at the point where it isfed by the preceding conveyor.
 7. Apparatus as claimed in claim 2wherein the discharge conveyor receives the contents from each saidregion of said container from said chute and delivers said articles toan intermediate conveyor, said intermediate conveyor being arranged todeliver said articles to a delivery conveyor arranged at right angles tosaid intermediate conveyor, each of said conveyors being provided withcontrollable driving means, said delivery conveyor being transverselyinclined at least at the point where it is fed by the precedingconveyor.
 8. Apparatus as claimed in claim 1 wherein said decanterapparatus is provided with tilting means operable to tilt a container insaid apparatus about a second horizontal axis which is perpendicular tothe axis about which said container is tilted towards one side thereof.9. Apparatus as claimed in claim 1 wherein the edge of the fence isinclined such that one end thereof against the container side is lowerthan the other end.
 10. Apparatus as claimed in claim 9 wherein the edgeof said fence is a series of steps.